Organometal halide Perovskites (Peros) have recently been discovered to have remarkable optoelectronic properties, eliciting research into their potential as photovoltaic and light-emitting diodes (LEDs). Pero LEDs offer many advantages, including high efficiencies, low processing temperatures, cost-effectiveness and scalable fabrication processes. For Pero solar cells, the highest power conversion efficiency has reached about 20%, which approaches the best efficiencies of copper indium, gallium selenide and cadmium telluride based thin film solar cells.
Most reported Pero-based LEDs have a multi-layer device architecture comprising, at a minimum, a Pero emissive layer, an electron transport layer (ETL), to assist electron injection across the Pero/cathode interface and a hole transport layer (HTL), to enhance hole injection across the Pero/anode side of the device. The use of an HTL and ETL has been shown to lower the hole/electron injection barriers, resulting in low operating voltage and high electroluminescence efficiency in OLEDs and quantum-dot LEDs. However, the multi-layer device architecture of Pero-based LEDs currently known in the art requires very complex fabrication steps that are not compatible with large scale printing processes.
Accordingly, what is needed in the art are Pero-based solar cells and Pero-based LEDs which utilize a scalable printing technique to fulfill the promise of large scale, low cost devices.